Drug Evaluation Committee Issues in Survival Time Analysis in Cost-Effectiveness Assessment
February 2020
In April 2019, a cost-effectiveness evaluation system was institutionalized to complement the existing drug pricing system.While ICER is defined as the incremental cost per unit of benefit provided by a new drug, the principle of this system is that the benefit in question is evaluated in terms of quality-adjusted life years (QALYs).For drugs whose clinical efficacy in clinical trials is evaluated using survival analysis, the ICER in cost-effectiveness analysis is likely to be calculated within the context of that survival analysis.In cost-effectiveness analysis, the analysis covers a long period that significantly exceeds the follow-up period of the clinical trial, and a decision considered optimal is made (whether the price of the new drug should be adjusted, and if so, how it should be adjusted).Because cost-effectiveness analyses have the characteristic of judging the relative merits of drugs based on estimation rather than statistical testing, it is often necessary to present data “as if one had observed what one had not actually observed.”Specifically, this may involve extrapolating a 15-year survival curve despite a clinical trial follow-up period of only 3 years, or—when patients in the control group are permitted to switch to the new drug after disease progression—using causal inference to estimate the overall survival time of the control group in the event that many patients switch to the new drug.
In FY2019 DS Subcommittee Continuing Project T5, based on Technical Support Document 14 (TSD14): Survival analysis for economic evaluations alongside clinical trials – extrapolation with patient-level data (2011), TSD16: Adjusting survival time estimates in the presence of treatment switching (2014), and TSD19: Partitioned Survival Analysis as a decision modeling tool (2017), we prepared a report summarizing the survival analysis techniques used in cost-effectiveness analysis and the challenges specific to such analyses.
Please note that any references to or citations of Technical Support Documents 14, 16, and 19 (Decision Support Unit, National Institute for Health and Care Excellence) in this report represent the interpretations of this Task Force, and NICE bears no responsibility whatsoever.Furthermore, not all TSDs were presented; only excerpts from some were included. The report incorporates the Task Force’s additional interpretations and is a summary prepared independently; it does not represent the views of NICE.
Issues in Survival Time Analysis in Cost-Effectiveness Evaluation (1.8MB)